Augmented Dickey fullest (ADF) test to four stationary to avoid for spurious regression. The study also makes use of the ordinary least square technique to measure determinants coefficient. The results indicate that the investment is significantly influenced real GDP and savings. Investment responded positively to output. While inflation negatively affects the investment, prompting policy maker to keep inflation under control. Further, factors such as inflation its influence is not statistically significant. Therefore the study found real GDP and savings to be the main determinants of investment in Namibia. The study recommends a review of the administration of the investment regime with the view to come up with a simpler and transparent system. In order to create a conducive environment to attract foreign direct investment (FDI) in the local economy government needs to improve on the quality of good governance, reduce bureaucracy and corruption. The study suggests that both expansionary fiscal and monetary policy can be applied simultaneously to stimulate GDP and savings to expend investments opportunities.